EP2843695A1 - Device, in particular end effector - Google Patents

Abstract

The invention relates to a device (1), in particular end effector, for receiving, transporting and / or positioning a wafer frame (2), which is covered with a carrier foil (3) for carrying a wafer (4), with a holder (5) Having vacuum nozzles (6) for holding the wafer frame (2) on the device, and having a centering device (28) which engages at least one stop (7) engageable in a recess (8) of the wafer frame (2) for centering the wafer frame (2) having. In order to achieve an exact positioning of the wafer frame, it is proposed that the holder (5) has Bernoulli nozzles (9, 90) for non-contact holding and moving of the wafer frame (2) in the direction of the stop (7), and that the stop (7) opposes the movement direction (11) generated by the Bernoulli nozzles (9, 90) is adjustably mounted from a starting position (12) into a different centering position (13).

Description

The invention relates to a device, in particular end effector, for receiving, transporting and / or positioning a wafer frame, which is covered with a carrier foil for carrying a wafer, with a holder having vacuum nozzles for holding the wafer frame to the device, and with a centering device comprising at least one engageable in a recess of the wafer frame stop for centering the wafer frame.

In order to remove a wafer frame, which is covered with a carrier foil for carrying a wafer, from a cassette, end effectors or grippers are known (US Pat. DE10259836A1 ), which hold the carrier film and / or the wafer frame with vacuum nozzles on the gripper. For centering the removed wafer frame of the gripper is provided with a stop for the wafer frame having centering device. For this purpose, the stop has a plurality of alignment pins which engage in recesses of the wafer frame and a stop element lying flat against the wafer frame. The disadvantage of such a centering device requires extremely precise guidance of the gripper so that stops and wafer frames can cooperate or can be reliably removed from the wafer frame. In addition, it is essential for this interaction that the wafer frame is aligned. Even slight deviations in the position of the wafer frame can lead to its wedging between the stop elements and thus prevent a secure holding a wafer frame. Due to thereby caused failures in semiconductor manufacturing or semiconductor processing lines, such as due to repairs under clean room conditions, production losses, etc., such grippers are only partially suitable in this field of technology.

Also known from the prior art are end effectors for wafer slices ( DE10161902A1 ). Such end effectors are with vacuum nozzles and Bernoulli nozzles provided to keep the wafer at the end effector. For centering the wafer on the end effector, a centering device is additionally provided, which pushes the wafer from a starting position into a centering position with diametrically opposed flat stops. This centering is supported by the concentric arrangement of the Bernoulli nozzles. The disadvantage is required after positioning of the wafer in the centering of a rotational orientation of the wafer, for which the holder is associated with a turntable. However, this leads disadvantageously to a considerable design effort and is also not suitable for centering wafer frames that hold a wafer over a carrier film.

The invention is thus based on the object, starting from the above-described prior art, to improve an end effector in such a way that the wafer together with the wafer frame is reliably and accurately centered relative to the end effector and nevertheless no impairment occurs in further handling steps. In addition, this device should also have a high stability.

The invention solves this problem by the fact that the holder Bernoullidüsen for non-contact holding and moving the wafer frame in the direction of the stop has, and that the stop is mounted against the direction of movement generated by the Bernoulli nozzle from a starting position in a different centering adjustable.

Assigns the holder Bernoullidüsen for non-contact holding and moving the wafer frame in the direction of the stop - among other things, using a caused by the Bernoulli effect hydrodynamic negative pressure - and is the stop against the direction of movement generated by the Bernoulli nozzle from a starting position in a different centering adjustable, a wafer frame can be gripped easily by the gripper and then reliably centered. The Bernoulli nozzles not only provide contactless holding of the wafer frame together with its carrier film and the wafer, but also also for a reliable displacement of the held wafer frame in the direction of the stop - regardless of the initial position of the gripped wafer frame. The device according to the invention can therefore prove to be extremely tolerant to positional deviations of the wafer frame to be gripped and thus also to ensure stable holding. In addition, the wafer frame is centered after moving the stop in the centering position, because the other alignment axis is determined by the recess engaging in stop. Furthermore, the movable support of the stop allows the stop to be removed from the wafer frame if this is necessary in the course of a processing step. In addition, the vacuum nozzles can take over the fixed storage of the wafer frame on the device. The stop therefore can thus avoid an impairment of further handling steps of the wafer frame.

In general, it is mentioned that the adjustable bearing of the stopper is of course provided not only in the centering position, but also from this back to the starting position. The Bernoulli effect describes the known effect of non-contact holding of a workpiece by the negative pressure caused by a gas flow exiting a nozzle. To form a Bernoulli effect for a circular workpiece, annularly arranged nozzles but also an annular nozzle can be used. Of course, other nozzle arrangements are conceivable with which the desired gas flow can be generated. Furthermore, it should be clarified that in the context of this invention, the use of a wafer frame also includes at least the carrier film and possibly the wafer equipped therewith.

The stability of the alignment of the wafer frame along an axis can be increased if the stopper forms two parallel centering lugs, which engage in a respective recess on the wafer frame. In addition, by means of the centering lugs and the corresponding recess of the wafer frame, a particularly accurate alignment between the stop and the wafer frame can be achieved. An exact one Adopting the centering position of the wafer frame on the device can thus be ensured.

If the centering device has a linear guide between stop and device, the centering position can be approached in a particularly simple manner.

In an advantageous embodiment of the device, the centering device has a compressed-air drive for moving the stop. Due to the low maintenance requirements of a pneumatic drive thus a particularly stable device can be created.

The constructional effort in the area of the guide of the stop can be further reduced if the centering device has a spring element connected to the stop for returning the stop, ie in its starting position.

If the Bernoulli nozzles are arranged asymmetrically distributed over the holder, the wafer frame can be moved by the resulting gas flow to structurally simple non-contact in the direction of the stop. In addition, it can be ensured that the Bernoulli nozzles always allow the wafer frame to approach or come to rest against the stop, even when the starting position is displaced into the centering position.

The region of the wafer frame which is reserved for the provision of the wafer or on which the wafer is provided can be protected against direct application by the Bernoulli nozzles by virtue of the Bernoulli nozzles being distributed in the film region between wafer frame and wafer on the holder. If the Bernoulli nozzles are arranged concentrically, it is possible to ensure uniform contactless movement of the wafer frame over the holder. In addition, safe handling can be achieved with a uniform holding force on the wafer frame or its carrier foil.

A stable, outwardly directed hydrodynamic negative pressure can be generated when the Bernoulli nozzles are directed obliquely outwards.

The propulsion of the wafer frame in the direction of the stop can be structurally made possible by the stop Bernoullidüsen parallel to the direction of movement and these opposite Bernoulli nozzles are directed from the inner center obliquely outwards.

For the aforementioned alternative or to improve the propulsion, the skew angle α of the stop Bernoullidüsen to the skew angle β of the opposite Bernoulli nozzles be different in size.

If a plurality of vacuum nozzles are provided on the outer edge of the holder, the wafer frame can be securely held on the device. In addition, direct acting loads on the carrier film or the wafer can thus be avoided and their damage can be ruled out - especially since it can not be ruled out that the wafer already has been sawn onto the carrier film and its detachment is to be feared. If the vacuum nozzles are provided on diametrically opposite projections of the holder, the wafer frame can be held particularly firmly on the device.

If the holder has an outer area and an inner area which is elevated therefrom and forms a stop edge for the wafer frame between them, the centering of the wafer frame can be additionally facilitated. Because of the stop edge, the number of possible starting positions can in fact be limited when gripping the wafer frame, in particular if a circumferential stop edge is provided.

Advantageously, the vacuum nozzles can be provided in the outer region and the Bernoulli nozzles in the inner region, in order to facilitate the contactless centering of the wafer frame and the fixed holding of the wafer frame in the centering position.

The stop edge can taper towards the inner region in order to reduce the risk of damage to the carrier film during gripping and subsequent centering of the wafer frame.

Fig. 1

eine Draufsicht auf eine Vorrichtung zum Aufnehmen, Transportieren und/oder Positionieren eines Waferrahmens,

Fig. 2

eine abgerissene und vergrößerte Draufsicht der Fig. 1,

Fig. 3

eine Schnittansicht nach III-III der nach Fig 1 dargestellten Vorrichtung,

Fig. 4

eine Draufsicht auf die Vorrichtung nach Fig. 1 mit gehaltenem Waferrahmen und

Fig.5

eine Draufsicht auf die Vorrichtung nach Fig. 1 mit gehaltenen Waferrahmen in dessen Zentrierlage.

In the figures, for example, the subject invention is illustrated in more detail with reference to a variant embodiment. Show it

Fig. 1

a top view of a device for receiving, transporting and / or positioning a wafer frame,

Fig. 2

a torn off and enlarged plan view of the Fig. 1 .

Fig. 3

a sectional view according to III-III of Fig. 1 illustrated device,

Fig. 4

a plan view of the device according to Fig. 1 with held wafer frame and

Figure 5

a plan view of the device according to Fig. 1 with held wafer frame in its centering position.

According to the FIGS. 1 . 3 and 4 For example, a top view of a device 1 designed as an end effector or gripper for picking up, transporting and / or positioning a wafer frame 2 is shown. The wafer frame 2, after the Figures 3 and 4 is shown in more detail, spans a carrier film 3, which carries a wafer 4 or semiconductor wafer cohesively. In order to firmly connect the covered wafer frame 2 with the device 1, the device 1 is provided with a holder 5, which are associated with vacuum nozzles 6 for sucking the wafer frame 2 to the holder or to the device 1. In addition, located on the device 1, a centering device 28 with a stop 7, which is formed in two recesses 8 on the wafer frame 2 engageable. The stop 7 serves to center the held wafer frame 2 or the wafer 4 on the device 1, after the wafer frame 2 has been recorded - for example, from a cassette, not shown. For a relative to the position of the wafer frame 2 tolerante recording of the device 1, the holder is provided with Bernoullidüsen 9, 90, not only keep the wafer frame 2 without contact, but also provided and / or configured such that the wafer frame 2 in the direction of Stops 7 moves and thus always pressed against the stop 7. Since the stop 7 engages in recesses 8 of the wafer frame, centering of the wafer frame 2 or of the wafer 4 along the movement axis 10 is achieved. The non-contact holding of the wafer frame 2 is made possible by the hydrodynamic negative pressure of the Bernoulli nozzles 9, 90 known in the prior art under the Bernoulli effect. By the stop 7 against the movement direction 11 generated by the Bernoullidüsen 9, 90 is mounted adjustable from a starting position 12 in a different centering position 13, the pressed on the stop 7 wafer frame 2 can be centered in the movement axis 11. This centering process is in the synopsis of 4 and 5 understand. The after Fig. 5 centered wafer frame 2 is subsequently reliably held in this centering position 13 by activating the vacuum nozzles 6. The Bernoulli nozzles 9, 90 can then be switched off. Thus, a device 1 is provided, which can hold a wafer frame 2 steadily under simple handling conditions, transport and position.

The wafer frame 2 is captured by the stopper 7 in a particularly positive fit by forming two parallel centering lugs 14. Since these are introduced into tapered recesses 8 on the wafer frame 2, inaccuracies in the orientation of the wafer frame 2 in the movement axis 10 are compensated. This is also automatically adjusted by the motion in the direction of movement 11 and / or 12 imposed on the wafer frame by the Bernoulli nozzles 9, 90.

The movement of the stop 7 is made possible by means of a linear guide 15 on the holder 5. Of course, this also other guides are conceivable. These between the bracket 5 and stop 7 provided linear guide 15 is realized by means of a piston rod 16 of a pneumatic drive 17. Advantageously, the compressed air drive 17 is supplied with compressed air via a valve 18, which is connected to the gas supply 19 of the Bernoulli nozzles 9, 90. This designed as a single-acting cylinder compressed air drive 17 is returned via a spring element 20 in its initial position 12. For this purpose, the spring element 20 engages the piston rod 16 and the housing 21 of the pneumatic drive 17.

How the particular Fig. 1 can be seen, the Bernoulli nozzles 9, 90 arranged asymmetrically distributed over the holder 5 concentric, so as to always maintain a direction of movement 11 of the wafer frame 2 in the direction of the stopper 7 upright. In a structurally simple manner, a smaller number of Bernoullidüsen 90 is provided on the stop 7 opposite edge of the holder 5, as in the Bernoullidüsen 9 at the edge of the holder 5, adjacent to the stop 7, the case.

The wafer is protected by a direct loading of the Bernoulli nozzles 9, 90, in which these Bernoulli nozzles 9, 90 are arranged distributed exclusively over the holder 5 in the area of the carrier film 3 between the wafer frame 2 and the wafer 4. In general, it is conceivable to arrange further Bernoulli nozzles not shown in the region of the center of the holder 3 or below the wafer 4, etc. Preferably, however, all Bernoulli nozzles 9, 90 are located in the region of the carrier film 3 between wafer frame 2 and wafer 4.

Again Fig. 3 can be seen, the Bernoullidüsen 9, 90 are aligned obliquely outwards. This is among other things for a uniform spacing when non-contact holding the wafer frame 2 is advantageous. In addition, in the Fig. 3 the oblique angles α and β of the stop Bernoullidüsen 9 and the Bernoullidüsen the stop Bernoullidüsen 9 opposite to recognize Bernoullidüsen 90. These skew angles α and β are different in size so as to securely impose a moving direction 11 on the wafer frame 2.

Like in the Fig. 2 to recognize the Bernoulli nozzles 9, 90 are also aligned differently in plan view. Namely, the stop-side Bernoulli nozzles 9 have a parallel flow direction 29 and the Bernoulli nozzles 90 opposite thereto a flow direction 30 diverging in a star-shaped manner. For this purpose, the stop Bernoullidüsen 9 are directed parallel to the direction of movement 11 and the opposite Bernoullidüsen 90 from the inner center 22, starting obliquely outwards. This further improves the accuracy of the centering of the wafer frame 2, since a game between wafer frame 2 and stop 7 is avoided due to the force thus developed against the stop 7.

The vacuum nozzles 6 are provided on the outer edge 23 of the holder 5, namely at diametrically opposite projections 24 which allows a compact design of the device 1.

Like also after the FIGS. 1 . 2 and 3 to recognize the holder 5 forms a circumferential stop edge 25 for the wafer frame 2 from. This is achieved structurally by an outer area 26 and an inner area 27 which is elevated therefrom. The contactlessly moving wafer frame 2 can not slide off from the holder 5 via this edge. The device 1 thereby offers the highest handling security in picking up, transporting and / or positioning a wafer frame 2 or wafer 4. Damage to the wafer frame 2 is avoided with the help of a stop edge 4 tapering towards the inside region 27.

The nozzles 6, 9 are structurally simply separated from each other by the outer region 26 and an inner region 27 which is elevated therefrom by providing the vacuum nozzles 6 in the outer region 26 and the Bernoulli nozzles 9, 90 in the inner region 27.

An exemplary embodiment of the wafer frame end effector or the device 1 will be explained in more detail by means of exemplary steps. For receiving the wafer frame 2, a short suction with the vacuum nozzles takes place 6, so that the inner region of the holder 5 comes close enough to the carrier film 3. Successively, the Bernoulli nozzles 9, 90 are activated in the inner region 27 of the holder 5 in order to form a negative pressure in accordance with the Bernoulli effect. Now, the wafer frame 2 hangs non-contact on the device 1 and can align itself laterally when the wafer frame 2 or frame, for example, in a transport box, inserted or removed from this.

The centering of the wafer frame 2 according to the invention takes place in a subsequent step. In this case, the wafer frame 2 strives against the stop 7 of the device 1 due to the asymmetric gas flow, which is caused by the asymmetrically arranged Bernoulli nozzles 9, 90 (see. Fig. 4 ). The centering of the wafer frame in the direction of the longitudinal axis of the device 1 is effected by the centering lugs 14 and the associated recesses 8 in the wafer frame 2. The wafer frame 2 is now in its starting position 12 of the centering process - as shown in FIG Fig. 4 can be seen. According to the invention, the stop 5 is now positioned along the linear guide track transversely to the longitudinal axis into the defined centering position 13. This is done in opposition to the direction of movement 11 predetermined by the asymmetric Bernoulli nozzles 9, 90. If the centering position 13 is reached, the vacuum nozzles 6 are activated in order to hold the wafer frame 2 firmly in the defined centering position on the device 1. According to the invention, the stop 7 can now be returned to its starting position 12 and the Bernoulli nozzles 9, 90 are switched off in order to make further work steps possible in a simple manner.

Claims (14)

Device, in particular end effector, for receiving, transporting and / or positioning a wafer frame (2), which is covered with a carrier film (3) for carrying a wafer (4), with a holder (5), the vacuum nozzles (6) for holding of the wafer frame (2) on the device, and having a centering device (28) which has at least one engageable in a recess (8) of the wafer frame (2) stop (7) for centering the wafer frame (2), characterized in that the holder (5) Bernoullidüsen (9, 90) for non-contact holding and moving the wafer frame (2) in the direction of the stop (7), and that the stop (7) against the direction of movement generated by the Bernoulli nozzles (9, 90) ( 11) is adjustably mounted from a starting position (12) in a different centering position (13). Apparatus according to claim 1, characterized in that the stop (7) forms two parallel centering lugs (14) which engage in a respective recess (8) on the wafer frame. Apparatus according to claim 1 or 2, characterized in that the centering device (28) has a linear guide (15) between stop (7) and device (1). Apparatus according to claim 1, 2 or 3, characterized in that the centering device (28) has a compressed-air drive (17) for moving the stop (7). Device according to one of claims 1 to 4, characterized in that the centering device (28) has a stop (7) connected to the spring element (20) for returning the stopper (7). Device according to one of claims 1 to 5, characterized in that Bernoulli nozzles (9, 90) are arranged asymmetrically distributed over the holder (5). Device according to one of claims 1 to 6, characterized in that the Bernoulli nozzles (9, 90) distributed in the film area between the wafer frame (2) and wafer (4) on the holder (5), in particular concentric, are arranged. Device according to one of claims 1 to 7, characterized in that the Bernoulli nozzles (9, 90) are directed obliquely outwards. Apparatus according to claim 8, characterized in that the stop Bernoullidüsen (9) parallel to the direction of movement (11) and the opposite Bernoullidüsen (90) are directed from the inner center obliquely outwards. Apparatus according to claim 8 or 9, characterized in that the oblique angle (α) of the stop Bernoullidüsen (9) to the oblique angle (β) of the opposite Bernoulli nozzles (90) is different in size. Device according to one of claims 1 to 10, characterized in that on the outer edge (23) of the holder (5), in particular on diametrically opposed projections (24) of the holder (5), vacuum nozzles (6) are provided. Device according to one of claims 1 to 11, characterized in that the holder (5) has an outer region (26) and a raised inner region (27), which between them a, in particular circumferential, stop edge (25) for the wafer frame (2 ) train. Device according to one of claims 12, characterized in that the vacuum nozzles (6) are provided in the outer region (26) and the Bernoulli nozzles (9, 90) in the inner region (27). Device according to one of claims 12 or 13, characterized in that the stop edge (25) to the inner region (27) tapers.

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